F-Secure modifies hosts file?

When I started my puter today F-secure was boasting about removing all sorts of trojans (I'd carefully added all these false positives to my previous antivir's exception list), it's a shame F-Secure is so overzealous when it comes to trainers, keygens and whatnot. Anyway, I can live with that (although if this keeps up I'm switching back to ESET) but what I really did NOT like is F-Secure messing with my hosts file; I've blocked Facebook servers through my hosts file so that bloody FB "Like button" spyware doesn't appear everywhere, and F-secure seemingly deleted it under the pretense of "Redirected_hosts_file", which I assume it does because it's been modified... by me. Anyhow, do I have to add the HOSTS file to F-Secure exception list for it to stop messing about or can I just re-do my hosts file as admin without worrying it'll detect my modifications as nefarious malware?

Sorry to bump this but nothing is helping and F-Secure keeps deleting my HOSTS file (in system32/drivers/etc) without my permission (as I added it to exclusions) still! PLEASE F-Secure, give users back control over their own computer and internet connection! At least make it so that F-Secure actually excludes files on the exclusion list! If I want to block Facebook and its APIs, Facebook Connect, Facebook Like etc. using my HOSTS file, that should be my prerogative. Given that Facebook has now infected a large portion of commercial websites I find it very strange that you do not allow users to block it using their HOSTS file, yet somehow F-Secure doesn't block Facebook's malware spreading all over the internet, or doesn't give an option to that effect. I know your job is hard and it's a precarious balancing act, but this is getting utterly ridiculous! You're not doing computer security any good by removing the user from the equation, that will only lead to increasing ignorance about computer security, indirectly making your job that much harder. In summary: Please make it so that users have the option of modifying their own HOSTS file without F-Secure stepping in to ruin the day. Please allow users to add file exclusions to the scanning options which aren't completely ignored by the program! This is absurd!